Capturing the complexity of human behavior has been a recurring theme in the Nebraska Symposium on Motivation. The contributors to this volume describe contemporary approaches to the modeling of complex cognitive and behavioral processes, ranging from molecular to molar phenomena. Although the essays reflect a wide range of theoretical and epistemic perspectives, they all incorporate complex frameworks of dynamic, systemlike relationships involving perception, learning, concept formation, emotion, motivation, intention, behavior, and the social context in which behavior occurs. The editors introduce the volume with a survey of the lifetime of the symposium, showing the development of ideas about behavioral and psychological complexity for over fifty years. A special feature of this collection is its emphasis on practical applications of the conceptual frameworks in which they work. The contributors provide examples of translational research ranging from clinical neuropsychology to self-actualization, from medical informatics to industrial psychology, from programmed learning to psychiatric rehabilitation.